1. Field of the Invention
The present invention relates to an image-taking lens system arranged to be capable of controlling and driving movable optical members provided for zooming, focusing, etc., and more particularly to a broadcasting television lens system.
2. Description of Related Art
FIG. 5 is a block diagram showing the arrangement of the conventional TV (television) lens system. As shown in FIG. 5, in the TV lens system, an image-taking lens barrel 102 is connected to a TV camera body 101 which is an image pickup apparatus. To the image-taking lens barrel 102 are also connected a zooming demand part 103 and a focusing demand part 104 which are included in an image-taking lens remote-control device. The operator of the TV lens system, such as a cameraman, can perform zooming and focusing of the TV lens system by operating the zooming demand part 103 and the focusing demand part 104 so as to obtain pictures according to situations.
FIG. 6 is a block diagram showing an arrangement for control over movable optical members such as zooming and focusing lenses in the conventional TV lens system. Referring to FIG. 6, when the operator operates a command member of the zooming or focusing demand part 103 or 104 shown in FIG. 5, a command operation amount detecting part 106 generates a command voltage 106a according to the amount of operation. The command voltage 106a is supplied to a command control part 107 which is composed of an analog circuit, etc. The command control part 107 converts the command voltage 106a into a command voltage signal 107a which conforms to the TV lens system. The command voltage signal 107a is inputted to the image-taking lens barrel 102.
At the image-taking lens barrel 102, the command voltage signal 107a inputted is supplied as a command value to a zooming and focusing driving control part 110 which is composed of an analog servo circuit, etc., for zooming, focusing, etc. An output signal 110a of the driving control part 110 is supplied to a motor arranged to actuate zooming, focusing or the like. A movable optical member 109 which is interlocked with the motor is then moved by the motor.
With regard to driving operations for zooming and focusing in the TV lens system, it has been required that the servo characteristic and operability of the TV lens system are arranged to be readily variable according to differences of shooting objects, such as drama shooting and sport relay broadcasting, etc., and also according to differences in operating method among camera operators. For example, a drama shooting operation to be performed within a studio requires a servo characteristic which permits a slow and smooth zooming operation, rather than a speedy zooming operation, and an operability which permits easy focusing at a focal length suited for shooting objects disposed within the studio. For
For an outdoor shooting such as a baseball relay broadcasting, on the other hand, a servo characteristic which permits zooming and focusing at a maximum speed for following a fast moving object and a ball and an operability which makes focusing on the infinity distance side of the lens easier than focusing on the nearest distance side of the lens.
While a TV lens system is thus required to have its servo characteristic and operability arranged to be readily variable according to the difference of shooting objects and the difference in liking among operators, the conventional TV lens system has been incapable of meeting this requirement. Some of known focusing and zooming demand parts have been arranged to vary the operability of the demand part by using a selection switch 108 as shown in FIG. 6 or a volume adjuster to shift the constant of an analog circuit within the demand part either continuously or noncontinuously in such a way as to vary a relation between the amount of operation and a command voltage.
However, the method for varying the operability by shifting the constant of the analog circuit disposed within the demand part by means of a switch or a volume adjuster to vary the command value in relation to the amount of operation has had the following shortcomings. According to that method, the servo characteristic of the TV lens system remains unchanged. Therefore, it has been impossible to improve the overall operability including the servo characteristic. Besides, switch-over of the relation between the demand operation amount and the amount of command by using the switch mounted on the zooming demand part or the focusing demand part is possible only for two or three fixed patterns of constants set beforehand by hardware means. It is, therefore, hardly possible to cope with all shooting situations as desired by the operator.
Another method of continuously varying the circuit constant by using a volume adjuster has been very troublesome, because it necessitates frequent volume adjustment, confirmation of the result of adjustment and repeating the adjusting operation for every shooting operation. Besides, the demand parts permit selection of only predetermined relations between command amounts and command voltages. Therefore, it has been difficult for the operator to readily change the existing setting and to store new setting as desired. Further, according to the prior art arrangement, items for which setting values are variable has been limited to the operation amount and the command amount of the operation member of the zooming or focusing demand part.
Further, as related art, there is Japanese Laid-Open Patent Application No. Hei 5-22729.
In view of the above-stated problems of the prior art, it is an object of the invention to provide means for varying a servo characteristic, operability, etc., for zooming and focusing without difficulty according to the shooting object and as desired by the operator.
To attain the above object, in accordance with an aspect of the invention, there is provided an image-taking lens system, which comprises an image-taking lens, lens driving control means for driving and controlling the image-taking lens, reading means for reading information from a storage medium in which a plurality of pieces of lens control information corresponding to conditions of shooting are stored, and setting means for setting control parameters of the lens driving control means on the basis of the information read by the reading means. The arrangement enhances, for example, servo characteristics and operability for zooming and focusing differently required by individual shooting objects and individual operators.
In the image-taking lens system, the image-taking lens is detachably mountable on a camera body, and the reading means is disposed at the image-taking lens.
The image-taking lens system further comprises remote operation control device for remotely operating and commanding the lens driving control means. The remote operation control means includes receiving means for receiving information read by the reading means and permits the operator of the system to vary the operating characteristic of a lens driving operation member according to the information received, i.e., as desired by the operator.
The image-taking lens system further comprises selection means for selecting necessary information from among a plurality of pieces of information read by the reading means. The setting means is arranged to set control parameters of the lens driving control means according to the information selected.
The above and further objects and aspects of the invention will become apparent from the following detailed description of a preferred embodiment thereof taken in connection with the accompanying drawings.